Python bindings for ftdi_read_data() broken

Regarding the Python bindings for libftdi, binary package python-ftdi 0.20-1 on precise, built from source package libftdi.
I is not possible to use the Python bindings for function ftdi_read_data().

Here is the C function description from the upstream documentation [1]:
int ftdi_read_data (
  struct ftdi_context * ftdi,
  unsigned char * buf,
  int size)
Parameters:
    ftdi pointer to ftdi_context
    buf Buffer to store data in
    size Size of the buffer
Return values:
    -666: USB device unavailable
    <0: error code from libusb_bulk_transfer()
    0: no data was available
    >0: number of bytes read

All my attempts to use the Python binding of this function failed.
Example:
 ReadData = ctypes.c_char * readCount
 readData = ReadData()
 actualReadCount = ftdi.ftdi_read_data(ftdiContext, ctypes.byref(readData), readCount)
Gives exception:

I am quite sure that there is no way to use it correctly.
The usage examples in the source package leave out the read function.

[1] http://www.intra2net.com/en/developer/libftdi/documentation/